1. Field of the Invention
The invention relates to a hose clamp with an essentially ring-shaped clamp body which encloses one end of a hose, with end areas of the clamp body overlapping in the clamped state, a clamping tool being used to spread the clamp body to a larger diameter against its own spring force. In particular, to such a hose clamp in which a first end area of the clamp body has a catch projection which is rearwardly offset relative to its front outer edge and which can be engaged with a second end area to achieve the spread state, the second end area having a longitudinally extended recess to hold the first end area which is correspondingly narrower.
2. Description of Related Art
A hose clamp of the type mentioned initially, which is usually also called a spring band clip, is already known from German Patent DE 30 41 106. In this known hose clamp, on the second end area there is a section which runs roughly radially, adjoined by a cover section which runs roughly at a right angle to the latter (i.e., in a generally tangential direction), so that it overlaps the front end of the first end area in the spread state. The spread state is implemented by the free edge of the first end area catching behind the section which runs roughly radially and under the cover section. In one embodiment, a bead which is pressed out of the material of the clamp body is provided in the first end area at a distance from the front free edge. This bead has a sharp front edge which is placed against the radial section in the spread position.
The known hose clamp has the advantage that it consists simply of a single piece and due to its design is rather small when installed. The disadvantage is that, in the various embodiments, the spread state is rather difficult to accomplish since the front free edge, itself, is used as a stop on the radial section, and therefore, cannot be used to catch or attach the clamping tool. In the aforementioned embodiment, which has the pressed-out bead, catching of the clamping tool on the free front edge is possible since the bead is offset rearward relative to the free front edge; however, in the clamped state the sharp edges of the bead are exposed so that there is the danger of injury to an installer who unintentionally comes into contact with the bead.
Another important disadvantage of this known hose clamp is that, moreover, there is the danger of overstretching of the hose clamp during spreading. This can happen relatively easily since the installer cannot see, during spreading, when the spread state is attained due to the fact that the interlocking between the bead and the radial section of the cover section is hidden. Spreading the hose clamp too much can result in damage which adversely affects its function due to overstretching of the clamp body; as a result, this can lead to leaks at the corresponding hose-connection piece coupling.